1. Field of the Invention
This invention relates, generally, to surgical tools and methods for their use. More particularly, it relates to a needle apparatus and method for marking the location of a lesion or a tumor in a breast or soft tissue.
2. Description of the Prior Art
Mammography enables the detection of very small lesions or tumors in a breast, even if the individual is experiencing no symptoms. However, if the lesion or tumor is non-palpable, it can be difficult for the surgeon to locate it and remove it through surgery.
A lesion may be non-palpable because it is very small. It may even be relatively large, but still non-palpable because it resides in a large breast or in a smaller breast but deep within the tissue mass.
In one prior art procedure, developed by Kopans, a hypodermic needle is placed into the breast so that the tip of the needle is near the lesion.
After the needle tip is positioned near the lesion, a stainless steel marking wire having a thin hooked distal end is introduced into the proximal end of the hollow bore of the needle and pushed toward the lesion until the thin hooked distal end of the marking wire protrudes from the distal end of the needle. The hook engages the breast tissue in the vicinity of the lesion and holds the marking wire in place, at least to some extent. Additional mammograms are then taken to verify the respective positions of the needle, the marking wire, and the hook. If the position of the apparatus is satisfactory, the needle is withdrawn from the breast, leaving the stainless steel marking wire unmoved because it is not connected to the needle. The surgeon then follows the marking wire to the lesion and removes the tissue in the vicinity of the hook.
The breast, however, must be compressed during the taking of a mammogram. The compression often causes the needle to migrate during mammagraphic filming; this causes uncertainty about the location of the hook.
Moreover, if the position of the hook is determined to be unsatisfactory, i.e., too far from the lesion, the hook cannot be extracted in any satisfactory manner. For example, forceful retraction of the marking wire can damage breast tissue; the hook might even break off and be lost in the tissue mass. Leaving a hook in the patient is unacceptable. Thus, another marking wire must be used in an additional attempt to position it closer to the lesion. It is not uncommon for several marking wires to protrude from a breast because multiple attempts to properly position a wire have been unsuccessful. This creates anxiety in the patient.
The most commonly used marking wire has an enlarged diameter near its distal end. The enlarged part purportedly makes the distal end palpable, but in practice it does not perform that intended function.
What is needed, then, is an improved method for marking the position of a breast or soft tissue lesion or tumor. The new method should facilitate additional attempts to better position the needle if the initial needle insertion proves to be unsatisfactory. There should be no tissue damage caused by withdrawing a wire hook and there should be no broken hooks left within a breast or other soft tissue.
However, it was not obvious to those of ordinary skill in this art how the needed method could be provided, in view of the art considered as a whole at the time the present invention was made.